Double Active Layers Constructed with Halide Perovskite and Quantum Dots for Broadband Photodetection

Herein, solution-processed, high-performance broadband (300-1100 nm) photodetectors based on double active layers incorporating narrow-bandgap CuInSe2 (CISe) quantum dots (QDs) and halide perovskite are devised. The CISe QDs/perovskite film as the photoactive layer boosts the photocurrent and suppresses dark current. Due to the joint light absorption effect of CISe QDs and halide perovskite, the photoelectric conversion capacity is improved. Furthermore, CISe QDs as an electron-blocking layer can effectively block electrons to the hole transport layer and reduce the thermal noise. The optimized photodetector exhibits responsivity over 150 mA W-1 in the visible and more than 20 mA W-1 in the near-infrared (800-1000 nm) ranges, specific detectivity of more than 7.0 x 10(12) Jones in the visible region and 7.7 x 10(11) Jones in the near-infrared region, a transient response time of 277 ns with the active area of 0.013 cm(2), and a linear dynamic range of approximate to 75 dB. Importantly, the CISe QDs layer makes the perovskite denser and more hydrophobic, thus improves the environmental and thermal stability of the detector, even extends the working temperature to exceeding 150 degrees C. The design concept and the considerable performance of this novel device provide a reference value for polychromatic light detection.